1. Field of the Invention
The present invention relates to a magnetic detection device for detecting a movement of an object of detection by utilizing a change in resistivity of a magnetoresistance effective element (MRE).
2. Description of the Related Art
Proximity rotation sensors mostly have a magnetic circuit structure in which a magnet for generating a bias magnetic field has the head plane lying parallel with a sensing element, i.e., the biasing magnet is mounted on the rear surface of the sensing element. This system periods detection by utilizing a deflection angle of the magnetic vector perpendicular to the direction of electric current through an MRE. At increased deflection angles, however, the output waveform undesirably involves division of a single wave peak into double wave peaks, causing malfunctioning.
To avoid occurrence of the divided or doubled wave peaks, U.S. Pat. No. 5,134,371 proposed a magnetic circuit structure in which a sensing element is disposed perpendicularly to the magnet head plane and contains MREs arranged at an inclination of about 45.degree. to a bias magnetic field.
The proposed structure, however, has a problem in that MREs, when so arranged, exhibit reduced sensitivity.